GAUHATI, India: Clashes between ethnic groups in India’s remote northeast has left at least 49 people dead in four days including 19 killed on Monday, officials said. Another 100,000 people have fled their homes, they said.

The fighting in Assam state began Friday when a group of young ethnic Bodo men were attacked after patrolling their villages. Bodo leaders blamed the incident on relatively recent settlers, most of whom are Muslims, sparking the clashes, said Assam Home Commissioner Subhash Das.

The 49 people killed included 15 people who were fatally shot when police opened fire on violent mobs in at least four different incidents, Das said. Police have been authorized to shoot at anyone fighting in the streets.

An indefinite curfew imposed Friday in the northern Assam districts of Udalguri and Darrang continued Monday with small breaks to allow people to buy essential supplies. ``The army, police and paramilitary are out in strength and we are mobilising all resources to stop the fighting,’’ said Assam government spokesman Himanta Biswa Sarma, who is also a senior minister. Ethnic Bodos and Muslim settlers in Assam have a history of conflict and have fought in the recent clashes with bows and arrows and spears and machetes, and have burned each other’s homes and property, officials said over the weekend.

More than 150 people have been injured in the violence and more than 100,000 have fled their homes in some 30 villages, Das said. Authorities are also investigating whether the National Democratic Front of Bodoland, a Bodo separatist group with a history of violence, has played a role in targeting Muslim settlers.

“We are investigating reports that NDFB militants have jumped into the fighting,’’ Assam chief minister Tarun Gogoi said late on Sunday. In an e-mail sent to journalists Sunday night, the group’s spokesman, S Sanjarang, denied any role in the fighting. Animosity between the Bodos and Muslim migrants stems from long-standing land disputes. The groups clashed sporadically throughout the 1990s, leaving at least 250 dead and an estimated300,000 displaced. Nearly 100,000 people are still living in makeshift relief camps.